Under the locust trees in the old city, the secrets of Guo Kexin and Zhu Sheng's entire youth are hidden. From children wearing crotchless pants to grabbing a candy, to teenagers sitting side by side under the locust tree doing homework, to adults who went to distant places and unexpectedly reunited, their stories are like the veins on the locust leaves, seemingly ordinary but already closely connected.
Guo Kexin has a soft temper but is tenacious. She always silently cleans up the mess when Zhu Sheng gets into trouble, and also hands him warm milk when he is frustrated. Zhu Sheng may seem careless, but he has remembered Guo Kexin's preferences for more than ten years. He will be the first to rush to her when she is bullied, and will also quietly ask someone to help her when she pursues her dreams. Time has stolen the youthful look, but it cannot steal the promise under the locust tree - some people say that it is difficult for childhood sweethearts to get married, but they have to spend more than ten years of companionship to prove that the warmest love is always hidden in the tenderness day after day. When the news of city demolition came and the old locust tree faced the fate of being cut down, they discovered that while protecting the tree, they were also protecting each other that had been engraved in their bones and blood.
